Fig. 1

a General dynamic regulation of membrane stress. 1. The cells produce an IMP of interest upon addition of the inducer. 2. Accumulation of IMPs causes IM stress signals. 3. A synthetic genetic circuit consisting of a controller and actuator senses and acts upon the IM stress. 4. IM stress diminishes which allows further IMP production. b Dynamic regulation of IM stress using a sRNA-based genetic circuit. 1. The cells produce an IMP of interest upon addition of the inducer. 2. Accumulation of IMPs activates the Cpx pathway. 3. The phosphorylated CpxR protein induces the circuit which results in the production of the designed sRNA (cpxQmut). 4. The sRNA represses translation of the IMP. 5. IM stress diminishes and the regulatory systems are downregulated. The amount of sRNA in the cell decreases which allows further IMP production. The cells can now re-enter this cycle. IM inner-membrane, IMP inner-membrane protein, OM outer-membrane, GOI gene of interest, RBS ribosome binding site